.wrapper{
    position: relative;
    width:600px;
    height:240px;
    border:1px solid red;
    
}
.wrapper span{
    position: absolute;
    top:90px;
    
    height:60px;
    width:24px;
    background-color:forestgreen;
    text-align: center;
    line-height: 60px;
    cursor: pointer;
    user-select: none;
    color:white;
    font-weight: 700;
}
.wrapper .right {
    right: 0;
}
.wrapper img{
    position:absolute;
    top:0;
    left:0;
    height:240px;
    width:600px;
}